Patent Application
20240021915
This application is based upon and claims the benefit of priority to Japanese Patent Application No. 2022-113427 filed on Jul. 14, 2022, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a battery temperature adjusting device configured to primarily adjust the temperature of a secondary battery that can be charged and discharged.
As a conventional art of the above type, for example, there is known a battery temperature adjusting device disclosed in Japanese unexamined patent application publication No. 2021-044135 (JP2021-044135A). This device is configured to adjust the temperature of a battery pack including a plurality of battery cells by exchanging heat between the battery cells with a heat medium. Here, the temperatures of the battery cells are different depending on layout, or arrangement, of the battery cells in the battery pack. Therefore, this device is configured as below to adjust the temperatures of the battery cells so that they are close to each other after temperature adjustment.
Specifically, this device is provided with a battery pack, a heat medium circuit, and a heat-transfer amount adjusting unit. The battery pack includes a first battery cell, a second battery cell electrically connected to the first battery cell, a first heat-exchange part for exchanging heat between the first battery cell and the heat medium (refrigerant), and a second heat-exchange part for exchanging heat between the second battery cell and the refrigerant. The heat medium circuit is arranged to flow the refrigerant at the adjusted temperature to the first heat-exchange part and the second heat-exchange part. Here, if the temperatures of the first and second battery cells are not adjusted, a temperature difference is generated between the first battery cell and the second battery cell due to the heat generated by charge and discharge under predetermined usage conditions. The heat-transfer amount adjusting unit is configured to adjust a first heat-transfer amount between the first battery cell and the refrigerant and a second heat-transfer amount between the second battery cell and the refrigerant so that the temperature difference between the first battery cell and the second battery cell after temperature adjustment is smaller than that when those first and second battery cells are not adjusted under the predetermined usage conditions.
The aforementioned battery temperature adjusting device disclosed in JP2021-044135A is configured to cool, using the refrigerant, the battery cells that generate heat during charge and discharge, thereby reducing a temperature difference between the battery cells in consideration of the layout of the battery cells; however, this technique does not disclose the technique of warming the battery cells during a cold period. Considering year-round use of batteries, both operations of cooling and warming the batteries are necessary in order to adjust the batteries to a proper temperature. Thus, there is a demand to provide a battery temperature adjusting device that can realize those operations.
The present disclosure has been made to address the above problems and has a purpose to provide a battery temperature adjusting device capable of adjusting the temperature of a battery by selectively cooling or warming the battery in response to a request for adjusting the temperature of a battery, which will be referred to as a battery temperature adjusting request.
To achieve the above purpose, one aspect of the present disclosure provides a battery temperature adjusting device comprising: a battery; a heat-exchange part configured to exchange heat between the battery and a heat medium; and a heat medium circuit configured to flow the heat medium to the heat-exchange part, the battery temperature adjusting device being configured to adjust a temperature of the battery by flowing the heat medium to the heat-exchange part through the heat medium circuit to exchange heat with the battery, wherein the heat medium circuit includes: a warming circuit configured to flow the heat medium with a raised temperature to the heat-exchange part to warm the battery; and a cooling circuit configured to flow the heat medium cooled to the heat-exchange part to cool the battery, and the battery temperature adjusting device further comprises a circuit switching unit configured to switch between the warming circuit and the cooling circuit to connect the warming circuit to the heat-exchange part when warming the battery and to connect the cooling circuit to the heat-exchange part when cooling the battery.
According to the above configuration, the heat medium circuit for flowing the heat medium to the heat-exchange part includes the warming circuit for flowing the temperature-increased heat medium (namely, a warming medium) to the heat-exchange part to warm the battery and the cooling circuit for flowing the cooled heat medium (namely, a cooling medium) to the heat-exchange part to cool the battery. When warming the battery, the circuit switching unit switches to connecting the warming circuit to the heat-exchange part, allowing the warming medium to flow to the heat-exchange part. Alternatively, when cooling the battery, the circuit switching unit switches to connecting the cooling circuit to the heat-exchange part, allowing the cooling medium to flow to the heat-exchange part.
The above-described aspect can selectively cool or warm the battery in response to a request for temperature adjustment of a battery.
A detailed description of several embodiments of a battery temperature adjusting device will now be given referring to the accompanying drawings.
A first embodiment will be described first referring to
In the present embodiment, each of the battery stacks 11A to 11E is constituted of a plurality of battery cells 13 arranged in a row and accommodated in a case 14. In
With the foregoing arrangement, each heat-exchange pipe 16 allows the heat medium flowing in from the first input/output port 16a to flow near the outer circumference and then near the center of each battery stack 11A to 11E, and finally flow out through the second input/output 16b. Thus, in each battery cell 13, the heat medium flows near the outer circumference and then flows near the center. In contrast, the heat medium flowing in the second input/output 16b flows near the center and then near the outer circumference, and finally flows out from the first input/output port 16a. Thus, in each battery cell 13, the heat medium flows near the center and then flows near the outer circumference.
As shown in
The first three-way valve 7 includes a first port 7a, a second port 7b, and a third port 7c. The second three-way valve 8 includes a first port 8a, a second port 8b, and a third port 8c. One end of the warming pipe 21 is connected to the first port 7a of the first three-way valve 7, while the other end of the warming pipe 21 is connected to the third port 8c of the second three-way valve 8. The first common pipe 17 is connected to the second port 7b of the first three-way valve 7. One end of the cooling pipe 31 is connected to the first port 8a of the second three-way valve 8, while the other end of the cooling pipe 31 is connected to the third port 7c of the first three-way valve 7. The second common pipe 18 is connected to the second port 8b of the second three-way valve 8. As the first three-way valve 7 and the second three-way valve 8, for example, electrically operated valves can be used.
Here, the first three-way valve 7 and the second three-way valve 8 switches to connecting the warming circuit 5 to each heat-exchange pipe 16 when each battery stack 11A to 11E is to be warmed, and switches to connecting the cooling circuit 6 to each heat-exchange pipe 16 when each battery stack 11A to 11E is to be cooled.
With the above configuration, the warming circuit 5 is configured to cause the first pump 23 to pressure feed the warming medium with a temperature raised by the heater 22 to each heat-exchange pipe 16 in order to warm the battery stacks 11A to 11E. The cooling circuit 6 is configured to cause the second pump 33 to pressure feed the cooling medium cooled by the cooler 32 to each heat-exchange pipe 16 in order to cool the battery stacks 11A to 11E.
In the present embodiment, the ECU4 controls the battery temperature adjusting device and corresponds to one example of a control unit of the present disclosure. Specifically, the first medium temperature sensor 24, the second medium temperature sensor 34, and a number of cell temperature sensors 19, are individually connected to the ECU 4. The first three-way valve 7, the second three-way valve 8, the heater 22, the first pump 23, the cooler 32, and the second pump 33 are also individually connected to the ECU 4. The ECU 4 controls those first three-way valve 7, second three-way valve 8, heater 22, first pump 23, cooler 32, and second pump 33 based on detected values of the corresponding sensors 19, 24, and 34.
Here, it is assumed that the battery pack 2 tends to decrease in performance as the temperature of each battery cell 13 is lower, and deteriorate when each battery cell 13 is used at 25° C. or higher, for example. Therefore, in order to ensure the performance of battery pack 2, it is necessary to use each battery cell 13 at around 25° C. as much as possible. To satisfy the above issues no matter how an electric vehicle is operated under any environmental conditions, consequently, the heat medium circuit 3 needs an enhanced performance or an increase size. However, this may result in higher cost and larger size (which worsens the ease of installation in a vehicle) of the battery temperature adjusting device 1. In the present embodiment, therefore, the ECU 4 executes the following control to warm and cool a battery pack 2, which will be referred to as a battery-pack warming-cooling control, in order to maximize the performance of the heat medium circuit 3, and ensure the performance and suppress the deterioration of the battery pack 2 at low costs.
In next step 110, the ECU 4 obtains a highest battery cell temperature TBCMX and a lowest battery cell temperature TBCMN from among the multiple battery cell temperatures TBCX taken in step 100.
In step 120, the ECU 4 takes the cooling medium temperature CTHW detected by the second medium temperature sensor 34 of the cooling circuit 6 and the warming medium temperature HTHW detected by the first medium temperature sensor 24 of the warming circuit 5.
In step 130, the ECU 4 determines whether or not the highest battery cell temperature TBCMX is higher than 25° C., which is a criterion for battery deterioration. When this determination result is affirmative (YES) in step 130, the ECU 4 proceeds to step 140. When this determination result is negative (NO) in step 130, the ECU 4 proceeds to step 190.
In step 140, the ECU 4 determines whether or not the cooling medium temperature CTHW is lower than the highest battery cell temperature TBCMX. When YES in step 140, the ECU 4 proceeds to step 150 to execute an operation mode 2 (DM2). When NO in step 140, the ECU 4 proceeds to step 170 to execute an operation mode 3 (DM3).
In the operation mode 2 (DM2), in step 150, the ECU 4 turns on the first three-way valve 7 and turns on the second three-way valve 8.
In the operation mode 2 (DM2), in step 160, the ECU 4 turns off the first pump 23 and turns on the second pump 33. Then, the ECU 4 returns to step 100.
In contrast, in step 170 following step 140, in the operation mode 3 (DM3), the ECU 4 turns off the first three-way valve 7 and turns off the second three-way valve 8.
In the operation mode 3 (DM3), in step 180, the ECU 4 turns off the first pump 23 and turns off the second pump 33. Then, the ECU 4 returns to step 100.
In contrast, in step 190 following step 130, the ECU 4 determines whether or not the warming medium temperature HTHW is higher than the lowest battery cell temperature TBCMN. When YES in step 190, the ECU 4 proceeds to step 200 to execute the operation mode 1 (DM1). When NO in step 190, the ECU 4 proceeds to step 170 to execute the operation mode 3 (DM3).
In the operation mode 1 (DM1), in step 200, the ECU 4 turns off the first three-way valve 7 and turns off the second three-way valve 8.
In the operation mode 1 (DM1), in step 210, the ECU 4 turns on the first pump 23 and turns off the second pump 33. Then, the ECU 4 returns to step 100.
According to the above battery-pack warming-cooling control, the ECU 4 takes the temperatures of the battery cells 13 constituting the battery pack 2, i.e., the battery cell temperatures TBCX, the temperature of the cooling medium flowing from the cooling circuit 6 to the battery pack 2, i.e., the cooling medium temperature CTHW, and the temperature of the warming medium flowing from the warming circuit 5 to the battery pack 2, i.e., the warming medium temperature HTHW. When the battery pack 2 needs to be warmed, i.e., the highest battery cell temperature TBCMX is below 25° C., and further when the warming medium temperature HTHW is higher than the lowest battery cell temperature TBCMN among the temperatures of all the battery cells 13, the ECU 4 executes the operation mode 1 (DM1). Specifically, the ECU 4 controls the first three-way valve 7, second three-way valve 8, first pump 23, and second pump 33 to continue to warm the battery pack 2 and flow the warming medium from the warming circuit 5 to the battery pack 2. In this case, even if the warming medium temperature HTHW is low, but if it is higher than the lowest battery cell temperature TBCMN, this warming medium is effective in warming the battery pack 2, thus ensuring the performance of the battery pack 2.
In contrast, when the battery pack 2 needs to be cooled, i.e., the highest battery cell temperature TBCMX is higher than 25° C., and further when the cooling medium temperature CTHW is lower than the highest battery cell temperature TBCMX, the ECU 4 executes the operation mode 2 (DM2). Specifically, the ECU 4 controls the first three-way valve 7, second three-way valve 8, first pump 23, and second pump 33 to continue to cool the battery pack 2 and flow the cooling medium from the cooling circuit 6 to the battery pack 2. In this case, even if the cooling medium temperature CTHW is high, but if it is lower than the highest battery cell temperature TBCMX, this cooling medium is effective in cooling the battery pack 2, thus suppressing deterioration of the battery pack 2.
Further, The ECU 4 executes the operation mode 3 (DM3) except when performing the foregoing operation mode 1 and operation mode 2. Specifically, the ECU 4 controls the first three-way valve 7, second three-way valve 8, first pump 23, and second pump 33 to stop warming and cooling of the battery pack 2 using the warming medium and the cooling medium. Here, for switching from the operation mode 2 to the operation mode 3, if the second pump 33 is turned off while the three-way valves 7 and 8 remain in the on-state, the cooling function on the battery pack 2 can be stopped. However, in the present embodiment, the three-way valves 7 and 8 are turned off simultaneously at that time, preventing unnecessary power consumption.
Furthermore, the ECU 4 turns off both the three-way valves 7 and 8 in the operation mode 1. When the battery pack 2 has low battery performance that needs to be warmed, both the three-way valves 7 and 8 are turned off, so that the load on the battery pack 2 can be reduced.
According to the battery temperature adjusting device 1 configured as above in the first embodiment described above, the heat medium circuit 3 for flowing the warming medium to the heat-exchange parts 12, i.e., the heat-exchange pipes 16, includes the warming circuit 5 configured to flow the heat medium with a raised temperature, i.e., the warming medium, to the heat-exchange pipes 16 to warm the battery pack 2, and the cooling circuit 6 configured to flow the heat medium cooled, i.e., the cooling medium, to the heat-exchange pipes 16 to cool the battery pack 2. When warming the battery pack 2, the circuit switching unit 9 switches between the warming circuit 5 and the cooling circuit 6 to connect the warming circuit 5 to the heat-exchange pipes 16, allowing the warming medium to flow to the heat-exchange pipes 16. In contrast, when cooling the battery pack 2, the circuit switching unit 9 switches between the circuits 5 and 6 to connect the cooling circuit 6 to the heat-exchange pipes 16, allowing the cooling medium to flow to the heat-exchange pipes 16. This makes it possible to selectively cool or warm the battery pack 2 in response to a request for adjusting the temperature of the battery pack 2 (the battery).
According to the configuration in this embodiment, when warming the battery pack 2, the circuit switching unit 9 switches between the circuits 5 and 6 to connect the heat-exchange parts 12 (i.e., the heat-exchange pipes 16) in the battery stacks 11A to 11E to the warming circuit 5, allowing the warming medium to flow to the heat-exchange pipe 16 in each of the battery stacks 11A to 11E. When cooling the battery pack 2, the circuit switching unit 9 switches between the circuits 5 and 6 to connect the heat-exchange pipes 16 in the battery stacks 11A to 11E to the cooling circuit 6, allowing the cooling medium to flow to the heat-exchange pipe 16 in each of the battery stacks 11A to 11E. This configuration can selectively cool or warm each of the battery stacks 11A to 11E constituting the battery pack 2.
According to the configuration in the present embodiment, when the heat medium flows in the heat-exchange pipes 16 through the first input/output ports 16a, the heat medium first circulates through the outer circumferential region of each battery stack 11A to 11E, then circulates through the central region of each battery stack 11A to 11E, and finally flows out through the second input/output ports 16b. In contrast, when the heat medium flows in the heat-exchange pipes 16 through the second input/output ports 16b, the heat medium first circulates through the central region of each battery stack 11A to 11E, then circulates through the outer circumferential region of each battery stack 11A to 11E, and finally flows out through the first input/output ports 16a. Thus, the heat medium flowing in the heat-exchange pipes 16 through the first input/output ports 16a first exchanges heat with the outer circumferential regions of the corresponding battery stacks 11A to 11E near the outer circumference, and then with the central regions of the corresponding battery stacks 11A to 11E near the center. Further, the heat medium flowing in the heat-exchange pipes 16 through the second input/output ports 16b first exchanges heat with the central regions of the corresponding battery stack 11A to 11E near the center, and then with the outer circumferential regions of the corresponding battery stacks 11A to 11E near the outer circumference. By selectively flowing the heat medium to the first input/output ports 16a and the second input/output ports 16b, either one selected from the outer circumferential region or the central region of each battery stack 11A to 11E can exchange heat with the heat medium prior to the other.
According to the present embodiment configured as above, when warming the battery pack 2, the circuit switching unit 9 switches to allowing the warming medium to flow in the heat-exchange pipes 16 through the first input/output ports 16a and flow out from the heat-exchange pipes 16 through the second input/output ports 16b. In contrast, when cooling the battery pack 2, the circuit switching unit 9 switches to allowing the cooling medium to flow into the heat-exchange pipes 16 through the second input/output ports 16b and flow out from the heat-exchange pipes 16 through the first input/output ports 16a. Therefore, when warming the battery pack 2, the warming medium flows in the heat-exchange pipes 16 through the first input/output ports 16a, enabling to individually warm the outer circumferential regions of the battery stacks 11A to 11E constituting the battery pack 2 first, and then warm the central regions of the battery stacks 11A to 11E. In contrast, when cooling the battery pack 2, the cooling medium flows in the heat-exchange pipes 16 through the second input/output ports 16b, enabling to individually cool the central regions of the battery stacks 11A to 11E constituting the battery pack 2, and then cool the outer circumferential regions of the battery stacks 11A to 11E. Consequently, when warming the battery pack 2, the outer circumferential region of each battery stack 11A to 11E constituting the battery pack 2 can be effectively warmed prior to the central region. When cooling the battery pack 2, the central region of each battery stack 11A to 11E constituting the battery pack 2 can be effectively cooled prior to the outer circumferential region.
According to the present embodiment configured as above, when warming the battery pack 2, the heat-exchange pipes 16 are connected to the warming circuit 5 by the circuit switching unit 9 to allow the warming medium to flow in the heat-exchange pipes 16 through the first input/output ports 16a, so that this warming medium circulates through the outer circumferential region of each battery stack 11A to 11E constituting the battery pack 2 first and then circulates through the central region of each battery stack 11A to 11E constituting the battery pack 2, and finally flows out through the second input/output 16b. In contrast, when cooling the battery pack 2, the heat-exchange pipes 16 are connected to the cooling circuit 6 by the circuit switching unit 9 to allow the cooling medium to flow in the heat-exchange pipes 16 through the second input/output ports 16b, so that this cooling medium circulates through the central region of each battery stack 11A to 11E constituting the battery pack 2, and then circulates through the outer circumferential region of each battery stack 11A to 11E, and finally flows out through the first input/output port 16a. Thus, when warming the battery pack 2, the outer circumferential region of each battery stack 11A to 11E constituting the battery pack 2 can be effectively warmed prior to the central region. When cooling the battery pack 2, the central region of each battery stack 11A to 11E constituting the battery pack 2 can be effectively cooled prior to the outer circumferential region.
Here, when it is requested to warm the battery pack 2 or each battery stack 11A to 11E, it is preferable to warm the outer circumferential region first, which is lower in temperature than the central region of the battery pack 2 or each battery stack 11A to 11E. Alternatively, when it is requested to cool the battery pack 2 or each battery stack 11A to 11E, it is preferable to cool first the central region first, which is higher in temperature than the outer circumferential region of the battery pack 2 or each battery stack 11A to 11E. In the present embodiment, when warming the battery pack 2, the outer circumferential region with a lower temperature than the central region in each battery stack 11A to 11E is warmed prior to the central region, so that each battery stack 11A to 11E and hence the battery pack 2 can be effectively warmed up. In contrast, when cooling the battery pack 2, the central region with a higher temperature than the outer circumferential region in each battery stack 11A to 11E is cooled prior to the outer circumferential region, so that each battery stack 11A to 11E and hence the battery pack 2 can be effectively cooled down.
A second embodiment will be described below referring to
This embodiment differs from the first embodiment in the configuration of the heat-exchange parts 12.
With the arrangement of the heat-exchange pipe 16 described above, the heat medium flowing in the heat-exchange pipe 16 through the first input/output port 16a flows through the outer circumferential region of each battery stack 11A to 11E, and then flows spirally from the outer circumferential region gradually toward the central region, and flows out from the central region at once through the second input/output 16b. At that time, in each battery cell 13, the heat medium flows through the outer circumferential region and then flows through the central region. In contrast, the heat medium flowing in the heat-exchange pipe 16 through the second input/output 16b flows through the central region of each battery stack 11A to 11E, and then flows spirally from the central region gradually toward the outer circumferential region, and flows out from the outer circumferential region at once through the first input/output port 16a. At that time, in each battery cell 13, the heat medium flows through the central region and then flows through the outer circumferential region.
The battery temperature adjusting device 1 configured as above in the second embodiment described above can achieve the same or similar operations and effects as those in the first embodiment, even though it is different in configuration of the heat-exchange pipes 16 (i.e., the heat-exchange parts 12) from the first embodiment.
A third embodiment will be described blow referring to
The battery temperature adjusting device 1 configured as above in the third embodiment can achieve the same or similar operations and effects as those in each of the foregoing embodiments, even though it is different in configuration of the battery pack 2 from each aforesaid embodiment.
A fourth embodiment will be described below referring to
The fourth embodiment differs in the configuration of the circuit switching unit 9 from each of the foregoing embodiments. In the foregoing embodiments, the circuit switching unit 9 is constituted of two three-way valves 7 and 8. In the fourth embodiment, as another example, the circuit switching unit 9 is constituted of a single six-way valve 41.
As shown in
The casing 42 is provided, on its outer periphery, with six ports; a first port 42a, a second port 42b, a third port 42c, a fourth port 42d, a fifth port 42e, and a sixth port 42f, each extending radially. Here, the first port 42a corresponds to the first port 8a of the second three-way valve 8, the second port 42b corresponds to the third port 7c of the first three-way valve 7, the third port 42c corresponds to the second port 8b of the second three-way valve 8, the fourth port 42d corresponds to the third port 8c of the second three-way valve 8, the fifth port 42e corresponds to the first port 7a of the first three-way valve 7, and the sixth port 42f corresponds to the second port 7b of the first three-way valve 7.
Herein, the first and second ports 42a and 42b of the six-way valve 41 are connected to the cooling pipe 31 and the third port 42c is connected to the second common pipe 18 for the second input/output ports 16b. Further, the fourth and fifth ports 42d and 42e are connected to the warming pipe 21, and the sixth port 42f is connected to the first common pipe 17 for the first input/output ports 16a.
Accordingly, in response to a cooling request for the battery pack 2, the six-way valve 41 is switched to the position shown in
The battery temperature adjusting device 1 configured as above in the fourth embodiment described above can achieve the same or similar operations and effects as those in each of the foregoing embodiments, even though it is different in configuration of the circuit switching unit 9 from the foregoing embodiments. In addition, in the fourth embodiment, a flow of the heat medium to the battery pack 2 can be switched by the single six-way valve 41. Thus, the battery temperature adjusting device 1 in this embodiment can have a compact configuration as compared with the battery temperature adjusting device 1 provided with the two three-way valves 7 and 8 in each foregoing embodiment.
A fifth embodiment will be described blow referring to
For recent batteries, the following issues are considered: (1) long charging time, (2) battery deterioration due to temperature rise, and (3) high battery cost. Here, the issue (1) can be addressed by increasing the capacity of a battery for quick charging, i.e., increasing the amount of current. Regarding the issue (2), as trade-off with increased capacity, i.e., increased current amount, the battery temperature rises due to quick charging (high current), leading to the progress of battery deterioration. Therefore, in order to suppress the rise in battery temperature during quick charging of the battery, it is conceivable to change the manner of cooling the battery from an air-cooling type to a water-cooling type. However, a pump is essential for the water-cooling type. The output power required for the pump depends on the cooling performance during quick charging. The temperature of the battery (e.g., a battery cell and the like) during quick charging is higher in a region of the battery closer to the center. To efficiently suppress the temperature rise of the battery, it is necessary to reduce the battery maximum temperature and thus to efficiently equalize the temperatures of the batteries. Here, since the pump is demanded to output excessive power during running, it is desirable to adopt as small a pump as possible. Regarding the issue (3), it is possible to achieve cost reduction through product improvement and mass production.
In the present embodiment, therefore, the battery pack 2 including the battery stacks 11A to 11E and related configurations are configured, differently from the foregoing embodiments, to control the flow rate of the cooling medium allowed to flow to each of the battery stacks 11A to 11E according to the temperatures of the battery stacks 11A to 11E.
In next step 210, the ECU 4 obtains the temperature of each battery stack 11A to 11F, i.e., the battery stack temperature TBSX2, from among the multiple battery cell temperatures TBCX taken in step 200. The ECU 4 can obtain this battery stack temperature TBSX2 from the maximum temperature of the battery cell temperatures TBCX in each battery stack 11A to 11F.
In step 220, the ECU 4 determines whether or not the battery stack temperature TBSX2 is 40° C. or higher. When this determination result is affirmative (YES) in step 220, the ECU 4 proceeds to step 230. When this determination result is negative (NO) in step 220, the ECU 4 proceeds to step 300.
In step 230, the ECU 4 determines whether or not the battery stack temperatures TBSX2 of all the battery stacks 11A to 11F exceed 40° C. The ECU 4 proceeds to step 240 when YES in step 230 or to step 280 when NO in step 230.
In step 240, the ECU 4 opens the electromagnetic valve 20 of the highest-temperature one of the battery stacks 11A to 11F.
In step 250, the ECU 4 closes the electromagnetic valves 20 of remaining battery stacks 11A to 11F.
In step 260, the ECU 4 turns on the first three-way valve 7 and turns on the second three-way valve 8 to cool the battery pack 2.
In step 270, the ECU 4 turns off the first pump 23 and turns on the second pump 33. Then, the ECU 4 returns to step 200.
The state of the battery temperature adjusting device 1 in cooling the battery pack 2 is illustrated in the schematic diagram in
In step 280 following step 230, the ECU 4 opens the electromagnetic valves 20 of all the battery stacks having a temperature of 40° C. or higher from among the battery stacks 11A to 11F.
In step 290, the ECU 4 closes the electromagnetic valves 20 of all the battery stacks having a temperature of less than 40° C. from among the battery stacks 11A to 11F, and then proceeds to step 260.
In contrast, in step 300 following step 220, the ECU 4 closes the electromagnetic valves 20 of all the battery stacks 11A to 11F.
In step 310, the ECU 4 turns off the first three-way valve 7 and turns off the second three-way valve 8 to stop cooling of the battery pack 2.
In step 320, the ECU 4 turns off the first pump 23 and the turns off the second pump 33. Then, the ECU 4 returns to step 200.
According to the battery temperature adjusting device 1 configured as above in the fifth embodiment described above, when a request for warming the battery pack 2 exists, that is, when the battery pack 2 needs to be warmed, the ECU 4 controls the circuit switching unit 9 to connect the heat-exchange parts 12 (i.e., the heat-exchange pipes 16) to the warming circuit 5 and further controls the electromagnetic valves 20. Thus, the heat-exchange pipes 16 are connected to the warming circuit 5, allowing the warming medium to flow in the heat-exchange pipes 16. In contrast, when a request for cooling the battery pack 2 exists, that is, when the battery pack 2 needs to be cooled, the ECU 4 controls the circuit switching unit 9 to connect the heat-exchange pipes 16 to the cooling circuit 6 and further controls the electromagnetic valves 20. Thus, the heat-exchange pipes 16 are connected to the cooling circuit 6, allowing the cooling medium to flow in the heat-exchange pipes 16. Accordingly, the ECU 4 controls the circuit switching unit 9 and simultaneously selectively controls the electromagnetic valves 20 to open, thereby selectively flowing the warming medium or the cooling medium to one or some of the heat-exchange pipes 16. This makes it possible to selectively warm or cool one or some of the battery stacks 11A to 11F, that is, a part of the battery pack 2 (the battery).
According to the configuration in the fifth embodiment, the electromagnetic valves 20 are provided individually in the heat-exchange pipes 16 of the battery stacks 11A to 11F constituting the battery pack 2. When cooling the battery pack 2, the electromagnetic valves 20 and others are controlled according to the temperatures of the corresponding battery stacks 11A to 11F to control a flow of the cooling medium with respect to each battery stack 11A to 11F. Specifically, according to the above-described battery-pack cooling control, only the electromagnetic valve(s) 20 corresponding to the high-temperature one(s) among the battery stacks 11A to 11F to control a flow of the cooling medium. Thus, the flow velocity of the cooling medium is accelerated in the heat-exchange pipe 16 of the high-temperature battery stack(s) among the battery stacks 11A to 11F, corresponding to the selectively opened electromagnetic valve(s) 20. This can enhance the cooling performance using the cooling medium in the high-temperature battery stacks 11A to 11F.
Herein, the results of temperature control on the battery pack 2 under the foregoing battery-pack cooling control are shown in graphs in
A sixth embodiment will be described blow referring to
The sixth embodiment differs from the fifth embodiment in the contents of the battery-pack cooling control.
When the process enters this routine, the ECU 4 executes the process in step 200 to step 230, and proceeds to step 400 when YES in step 230 or instead to step 430 when NO in step 230.
In step 400, the ECU 4 determines the highest-temperature one of the battery stacks 11A to 11F.
In next step 410, the ECU 4 determines whether or not the highest-temperature one of the battery stacks 11A to 11F has been changed to another.
The ECU 4 proceeds to step 420 when YES in step 410 or returns to step 200 when NO in step 410.
In step 420, the ECU 4 turns off the first pump 23 and turns off the second pump 33.
The ECU 4 executes the process in step 240 to step 270 and then returns to step 200.
In contrast, in step 430 following step 230, the ECU 4 determines the battery stack(s) exceeds 40° C. from among the battery stacks 11A to 11F.
In step 440, the ECU 4 determines whether or not the battery stack(s) with a temperature exceeding 40° C. among the battery stacks 11A to 11F has been changed to another. The ECU 4 proceeds to step 450 when YES in step 440 or returns to step 200 when NO in step 440.
In step 450, the ECU 4 turns off the first pump 23 and turns off the second pump 33.
The ECU 4 thereafter executes the process in steps 280, 290, 260, and 270, and returns to step 200.
According to the battery temperature adjusting device 1 configured as above in the sixth embodiment described above, in the foregoing battery-pack cooling control, when opening the corresponding electromagnetic valves 20 to cool the high-temperature battery stack(s) among the battery stacks 11A to 11F, the ECU 4 stops each of the first pump 23 and the second pump 33 before opening the corresponding electromagnetic valves 20, different from the fifth embodiment. Consequently, a pressure difference of the cooling medium between the inlet and the outlet of the corresponding electromagnetic valve 20, namely, a valve front-rear differential pressure, decreases. Accordingly, a coil used in the electromagnetic valves 20 can be reduced in size, leading to cost reduction of the electromagnetic valves 20.
A seventh embodiment will be described blow referring to
In the seventh embodiment, assuming that the system configuration shown in
When the process enters this routine in
In contrast, after executing the process in step 210 to warm the battery pack 2, the ECU 4 controls, in step 510, the electromagnetic valves 20 so that the flow rate of warming medium is higher in the outer circumferential region of the battery pack 2 than other regions thereof. For example, in
According to the battery temperature adjusting device 1 configured as above in the seventh embodiment described above, when a warming request for the battery pack 2 exists, that is, when the battery pack 2 needs to be warmed, that is, it is preferable to warm the battery pack 2 from the outer circumferential region with a lower temperature than the central region. When a cooling request for the battery pack 2 exists, that is, when the battery pack 2 needs to be cooled, it is preferable to cool the battery pack 2 from the central region with a higher temperature than the outer circumferential region. According to the above-described configuration, the heat-exchange parts 12 (the heat-exchange pipes 16) are arranged to flow the cooling medium at a higher flow rate through the central region than the outer circumferential region in order to cool the battery pack 2, so that a high flow rate of cooling medium flows through the central region of the battery pack 2. In contrast, the heat-exchange pipes 16 are arranged to flow the warming medium at a higher flow rate through the outer circumferential region than the central region in order to warm the battery pack 2, so that a high flow rate of warming medium flows through the outer circumferential region of the battery pack 2. This arrangement enables to effectively cool the central region of the battery pack 2 (the battery) in cooling the battery pack 2 and to effectively warm the outer circumferential region of the battery pack 2 in warming the battery pack 2.
An eighth embodiment will be described below referring to
This eighth embodiment differs from the fifth to seventh embodiments in the arrangement of the heat-exchange pipes 16 and the electromagnetic valves 20 in the battery pack 2.
According to the battery temperature adjusting device 1 configured as above in the eighth embodiment described above, different from the sixth and seventh embodiments, the battery pack 2 constituted of six battery stacks 11A to 11F is divided into three areas, that is, the outermost area for the rightmost battery stack 11A and the leftmost battery stack 11F, the second outermost area for the battery stacks 11B and 11E more inside than the battery stacks 11A and 11F, and the central area for the battery stacks 11C and 11D, and three electromagnetic valves 20A to 20C are provided one for each of those three areas to control the cooling medium and the warming medium to flow in each area. Thus, the present embodiment can control a flow of the cooling medium and a flow of the warming medium in each area by use of the electromagnetic valves 20A to 20C, fewer than the number of the battery stacks 11A to 11F. Therefore, the battery temperature adjusting device 1 can be simplified in structure and reduced in size by the reduced number of electromagnetic valves 20A to 20C.
A ninth embodiment will be described below referring to
The ninth embodiment differs from each of the foregoing embodiments in the configuration of the heat-exchange pipes 16 in the battery pack 2.
According to the battery temperature adjusting device 1 configured as above in the ninth embodiment, among the six battery stacks 11A to 11F arranged in parallel, the battery stacks 11B to 11E in the areas closer to the center in the arrangement direction of the battery stacks 11A to 11F are provided with more heat-exchange pipes 16 to increase the total surface area of pipe passage walls. With this configuration, a flow rate of cooling medium and a flow rate of warming medium can be different for arrangement area of the battery stacks 11A to 11F. Furthermore, the battery temperature adjusting device 1 can be simplified in structure and reduced in size due to the absence of an electromagnetic valve and others.
A tenth embodiment will be described below referring to
The tenth embodiment differs from the ninth embodiment in the configuration of the heat-exchange pipes 16 in the battery pack 2.
According to the battery temperature adjusting device 1 configured as above in the present embodiment, the passage areas of the heat-exchange pipes 16 are set larger for the battery stacks 11B to 11E located in the areas closer to the center in the arrangement direction of the battery stacks 11A to 11F, so that the cooling medium flowing through those heat-exchange pipes 16 has a lower pressure drop, allowing the flow rate of that cooling medium to increase. With this configuration, a flow rate of cooling medium and a flow rate of warming medium can be different for each arrangement area of the battery stacks 11A to 11F. Furthermore, the battery temperature adjusting device 1 can be simplified in structure and reduced in size due to the absence of an electromagnetic valve and others.
An eleventh embodiment will be described below referring to
The eleventh embodiment differs from each of the foregoing embodiments in the configuration of the heat-exchange pipes 16 in the battery pack 2.
According to the battery temperature adjusting device 1 configured as above in the present embodiment, for the battery stacks 11A to 11F arranged in parallel, the heat-exchange pipes 16 are placed at smaller intervals at positions closer to the center in the longitudinal direction of each battery stack 11A to 11F to increase the number of heat-exchange pipes 16 in order to increase the total surface area of pipe passage walls. With this configuration, a flow rate of cooling medium and a flow rate of warming medium can be different for each area in the longitudinal direction of the battery stacks 11A to 11F. In addition, the battery temperature adjusting device 1 can be simplified in structure and reduced in size due to the absence of an electromagnetic valve and others.
A twelfth embodiment will be described below referring to
The twelfth embodiment differs from the eleventh embodiment in the configuration of the heat-exchange pipes 16 in the battery pack 2.
According to the battery temperature adjusting device 1 configured as above in the present embodiment, in addition to the configuration of the eleventh embodiment, for the parallel battery stacks 11A to 11F, the heat-exchange pipes 16 are additionally arranged in parallel to the longitudinal direction of each battery stack 11A to 11F to increase the number of heat-exchange pipes 16 for the battery stacks 11B to 11E in or close to the central area. With this configuration, a flow rate of cooling medium and a flow rate of warming medium can be increased in or close to the central area of the battery pack 2 including the battery stacks 11A to 11F. In addition, the battery temperature adjusting device 1 can be simplified in structure and reduced in size due to the absence of an electromagnetic valve and others.
A thirteenth embodiment will be described below referring to
The thirteenth embodiment differs from the ninth embodiment in the configuration of the heat-exchange pipes 16 in the battery pack 2.
According to the battery temperature adjusting device 1 configured as above in the present embodiment, among the battery stacks 11A to 11F arranged in parallel, the battery stacks 11B to 11E in the areas closer to the center are provided with the heat-exchange pipes 16 with longer length and larger distribution to increase the total surface area of pipe passage wall. With this configuration, a flow rate of cooling medium and a flow rate of warming medium can be different for each arrangement area of the battery stacks 11A to 11F. In addition, the battery temperature adjusting device 1 can be simplified in structure and reduced in size due to the absence of an electromagnetic valve and others.
The foregoing embodiments are mere examples and give no limitation to the present disclosure. The present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof.
(1) In the foregoing fifth and eighth embodiments, for the battery stacks 11A to 11F constituting the battery pack 2, the electromagnetic valves 20, and 20A to are provided just behind the second input/outputs 16b of the heat-exchange pipes 16, that is, on the inlet side of the cooling medium in the battery stacks 11A to 11F. As an alternative, in battery stacks of a battery pack, electromagnetic valves may be provided just behind first input/output ports of heat-exchange pipes, that is, on an outlet side of the cooling medium in the battery stacks. In this case, the front-rear differential pressure of each electromagnetic valve is lower than the above configuration, so that a coil of each electromagnetic valve can be reduced in size and hence the electromagnetic valve can be reduced in size.
(2) In the foregoing tenth embodiment, the heat-exchange pipes 16 each having a circular cross-section have a larger outer diameter for the battery stacks 11A to 11F located close to the central area, among the six battery stacks 11A to 11F arranged in parallel, in order to increase the total surface area of pipe passage walls. As an alternative, for the battery stacks 11A to 11F located in the areas closer to the center, heat-exchange pipes may have an elliptic cross-sectional shape with a longer major axis to increase the outer circumferential length per equal cross-sectional area.
(3) In the foregoing ninth to thirteenth embodiments, the heat-exchange pipes 16 (i.e., the heat-exchange parts 12) are not provided with any electromagnetic valve, but alternatively the heat-exchange pipes (i.e., heat-exchange parts) may be individually provided with electromagnetic valves. In this case, when one or some of the electromagnetic valves are selectively opened, allowing the cooling medium or warming medium to flow to only the battery stack(s) located in a specified area(s) among the battery stacks arranged in parallel.
The present disclosure is utilizable for adjustment of the temperature of a secondary battery which is mounted in an electric vehicle.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-113427 | Jul 2022 | JP | national |
